DAVIE - A troublesome back injury has kept Miami Dolphins rookie tight end Arthur Lynch from playing in the exhibition season.

Lynch, the Dolphins' first of two 2014 fifth-round pick, has been nursing his back injury since May.

Lynch has participated in practice on a limited basis for weeks, but hasn't been cleared to play in any preseason games. The injury, which limits his mobility, could land the former University of Georgia standout on injured reserve.

“It’s tougher, it’s tougher. Without a doubt, it’s tougher," coach Joe Philbin said when asked about not being able to evaluate Lynch properly during training camp.

"You want to see our guys respond [in a game]. As I’ve said many times, we spend a lot of time removing ourselves [in practice] to the degree that we can as coaches, but when you’ve got 20 coaches out there on the field and the players are right there, it’s hard to keep your mouth shut," Philbin said. "In a game, it’s a lot easier for us to step back and let those guys see what they can do, and that’s an important part of the evaluation. [Playing games] is very, very important [to assess] the work ethic, the fundamental development and the team work. At the end of the day, we play games. You’ve got to figure out how guys play in games.”

Lynch's back issues, which a league sources says involve his spine, could put the Dolphins in a bind when it comes to finding enough healthy tight ends for the 53-man roster.

Charles Clay, the team's starter, is nursing a knee injury that has limited his practice participate, and involvement in the exhibition season. Clay has only played in the first quarter of Miami's 25-20 win over Dallas, and has sat out the rest of the preseason. Clay will likely be held out of Thursday night's preseason finale against the St. Louis Rams.

Dion Sims, who started five games as Miami's in-line tight end last year, has stepped up, and is developing nicely in his second season. But the Dolphins need to find another tight end who can contribute in the team's numerous two tight end packages, which is a staple formation of Bill Lazor's offense.

If Lynch isn't able to contribute early, or at all this season, it increases the odds that rookie tight end Gator Hoskins, Kyle Miller, who spent last year on Miami's practice squad, Brett Brackett or Evan Wilson could survive Saturday's roster cuts, making it to the Dolphins' 53-man roster.

It is also possible the Dolphins could scour the waiver wire to find tight end help. Ironically, the Dolphins cut former third-round pick Michael Egnew last week, and the former Missouri standout was claimed by the Detroit Lions on Tuesday.

Hoskins, an undrafted rookie from Marshall, showed a ton of promise early, but a hamstring injury slowed his development. However, he played in his first preseason game last Saturday and scored on a 27-yard touchdown pass from Matt Moore in the fourth quarter.

Brackett, who was released earlier in camp but brought back because of Clay's injury, has contributed five receptions for 69 yards during the exhibition season. But his blocking and special teams work needs to improve.